Does systemic clarithromycin therapy have an inhibitory effect on tympanosclerosis? An experimental animal study

From Evidence to Clinical Guidelines in Antibiotic Treatment in Acute Otitis Media in Children

Acute otitis media (AOM) in children represents a public health concern, being one of the leading causes of health care visits and antibiotic prescriptions worldwide. The overall aim of this paper is to unravel the major current insights into the antibiotic treatment of AOM in children. Our approach is three-fold: 1. a preclinical evaluation of antibiotics in animal models of AOM stressing on the advantages of different species when testing for different schemes of antibiotics; 2. an overview on the new antimicrobial agents whose efficacy has been demonstrated in refractory cases of AOM in children; and 3. an analysis of the different guidelines stressing on the differences and similarities between the various schemes of antibiotic treatment. The preferred therapeutic agents remain amoxicillin and the amoxicillin-clavulanate combination for AOM caused by Streptococcus pneumoniae, whereas oral cephalosporin is preferred in AOM due to Moraxella catarrhalis and Haemophilus influenzae. As for the second and third line antimicrobial treatments, there is a wide variety of suggested antibiotic classes with variations in duration and posology. The decision to prescribe antimicrobial treatment as a first-line choice is based on the severity of the symptoms in 16 of the guidelines included in this review.

Panel 1: Biotechnology, biomedical engineering and new models of otitis media

OBJECTIVE

To summarize recently published key articles on the topics of biomedical engineering, biotechnology and new models in relation to otitis media (OM).

DATA SOURCES

Electronic databases: PubMed, Ovid Medline, Cochrane Library and Clinical Evidence (BMJ Publishing).

REVIEW METHODS

Articles on biomedical engineering, biotechnology, material science, mechanical and animal models in OM published between May 2015 and May 2019 were identified and subjected to review. A total of 132 articles were ultimately included.

RESULTS

New imaging technologies for the tympanic membrane (TM) and the middle ear cavity are being developed to assess TM thickness, identify biofilms and differentiate types of middle ear effusions. Artificial intelligence (AI) has been applied to train software programs to diagnose OM with a high degree of certainty. Genetically modified mice models for OM have further investigated what predisposes some individuals to OM and consequent hearing loss. New vaccine candidates protecting against major otopathogens are being explored and developed, especially combined vaccines, targeting more than one pathogen. Transcutaneous vaccination against non-typeable Haemophilus influenzae has been successfully tried in a chinchilla model. In terms of treatment, novel technologies for trans-tympanic drug delivery are entering the clinical domain. Various growth factors and grafting materials aimed at improving healing of TM perforations show promising results in animal models.

CONCLUSION

New technologies and AI applications to improve the diagnosis of OM have shown promise in pre-clinical models and are gradually entering the clinical domain. So are novel vaccines and drug delivery approaches that may allow local treatment of OM.

IMPLICATIONS FOR PRACTICE

New diagnostic methods, potential vaccine candidates and the novel trans-tympanic drug delivery show promising results, but are not yet adapted to clinical use.

Animal models of acute otitis media - A review with practical implications for laboratory research

Considerable animal research has focused on developing new strategies for the prevention and treatment of acute otitis media (AOM). Several experimental models of AOM have thus been developed. A PubMed search of the English literature was conducted from 1975 to July 2016 using the search terms "animal model" and "otitis media" from which 91 published studies were included for analysis, yielding 123 animal models. The rat, mouse and chinchilla are the preferred animals for experimental AOM models with their individual advantages and disadvantages. The most common pathogens used to create AOM are Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Streptococcus pneumoniae (types 3, 23 and 6A) and non-typeable Haemophilus influenzae (NTHi) are best options for inoculation into rat and mouse models. Adding viral pathogens such as RSV and Influenza A virus, along with creating ET dysfunction, are useful adjuncts in animal models of AOM. Antibiotic prophylaxis may interfere with the inflammatory response without a significant reduction in animal mortality.

The effect of caffeic acid phenethyl ester (CAPE) on tympanosclerosis

OBJECTIVE

To investigate the effects of caffeic acid phenethyl ester (CAPE) on tympanosclerosis.

MATERIALS AND METHODS

Thirty-two male Sprague Dawley rats were separated into 4 groups as CAPE (n = 10), alcohol (n = 10), control (n = 8) and normal (n = 4) groups. All tympanic membranes except normal group were myringotomised and type 3 Streptococcus pneumoniae strains was injected into their middle ears. Myringotomies were repeated for 5 weeks. Intraperitoneal (i.p) CAPE were administrated to the CAPE group at 10 μmol/kg/day and 10% ethyl alcohol administrated to the alcohol group for 5 weeks. The control group were left untreated. Findings of myringosclerosis were recorded by otomicroscope at sixth week. Then, all rats were sacrificed and tympanic membrane thickness and severity of middle ear mucosal inflammation evaluated histopathalogically.

RESULTS

Severity of myringosclerosis was significantly higher in the alcohol and control groups compared to the CAPE group (p < 0.001), but was not significant when alcohol and control groups were compared (p = 0.17). The tympanic membrane thickness measured in the alcohol and control groups were significantly higher compared to the CAPE group (p < 0.001), but was not significant when alcohol and control groups were compared (p = 0.17). The severity of inflammation in the middle ear mucosa was significantly higher in the alcohol and control groups compared to the CAPE group (respectively, p < 0.001, p = 0.03). The severity of inflammation in the middle ear mucosa was not significant between alcohol and control groups (p = 0.30).

CONCLUSION

CAPE has anti-inflammatory and antioxidant effects on the development of MS in myringotomized rats, so reduces the severity of tympanosclerosis.